An electrical apparatus is typically equipped with a battery for supplying electric power in order to secure its normal operation while there is no external power supply connected to the electrical apparatus. In addition, batteries can make life more convenient or make work easier by way of allowing a user of a portable electrical apparatus, such as a cell phone, a notebook computer, a plane computer or a personal digital assistant (PDA) to take his/her portable electrical apparatus moving around freely without the hindrance of an external power supply connected therewith.
However, the power supply can be terminated when charge of the batteries is exhausted, and interruption and inconvenience may occur. For example, it would be an unpleasant experience to a cell phone user, when the conversation is broken by the termination of power supply due to the battery exhaust.
To solve the problem, the charge level of a battery equipped in a portable electrical apparatus is monitored and the remaining charge level is graphically displayed by an icon to remind the user connecting an external power supply to the portable electrical apparatus on time in order to secure its normal operation.
However, the icon merely reveals a rough estimate of how much time remains before the battery is exhausted, the user can not determine the exact value of the remaining time and when he/she should connect the external power supply to the portable electrical apparatus before the battery exhausted.
At the present time, the portable electrical apparatus is usually equipped with lithium (Li) batteries (also referred as Li-ion polymer battery) that are rechargeable and has higher power density, lighter weight and longer lifetime in comparison with nickel (Ni) batteries.
In order to extend the available time of the portable electrical apparatus or the battery life, a battery management method is recently adopted. Several battery power modes, such as normal operation mode and power saving mode, are provided by the application programs established in the portable electrical apparatus. The user can select one of the battery power modes in accordance with the current operating status of the portable electrical apparatus, as a result the power usage effectiveness of the battery can be improved, and the available time of the portable electrical apparatus or the battery life can be also prolonged.
However, there are still problems to extending the available time of the portable electrical apparatus or the battery life. On one hand, since the users should select the battery power modes by themselves, but most of the users are not capable to select the proper mode to use power more effectively, thus the available time of the portable electrical apparatus or the battery life can not be extended by above approaches. On the other hand, improper battery power mode may cause a poor performance of the portable electrical apparatus. For example, when a high energy consuming application program, such as a game application, is performed on a portable electrical apparatus, but the operation status of the portable electrical apparatus is still set in the power saving mode, while the center process unit (CPU) of the portable electrical apparatus may run in a reduced frequency, image lag may thus occur and the performance of the portable electrical apparatus is deteriorated. In some other case, when the battery charge level (of a Li battery) is depleted to a predetermined level, and the portable electrical apparatus is still put in a normal operation mode, the charge of the battery may be exhausted sooner than expected, so as to cause the portable electrical apparatus shutdown unexpectedly. Besides a large current drain in a short time may cause the battery available capacity and longevity decreased significantly.
Therefore, there is a need of providing an improved a method for monitoring and managing battery charge level and an apparatus for performing the same to obviate the drawbacks encountered from the prior art.